Clutch pulley



Patented Nov. 2', 1937.

UNITED STATES PATENT OFFICE l' CLUTCH PULLEY.-

Robert L. Brown1ee, Chicago, Ill. Application January 22, 1937, Serial No. 121,896

` claims. `(cru- 239.241)

My invention relates to clutch pulleys, and,

more particularly to those receiving a belt drive, and my main object is to provide a. pulley of this kind in which only a light pressure will eii'ect a 5 firm engagement of the clutch.

A further object of the invention is to design a clutch pulley in which a very small amount of 4travel will be required between the clutch eleload automatically increases the engaging'action.

between the belt and the pulley.

An additional object of the invention is to provide a very compact clutch assembly employing a o V-belt and requiring a minimum amount o1' longitudinal room.

An important object of the invention is to construct a clutch pulley of few and simple parts and which can be manufactured at small cost.

With the above objects in view, and any others lwhich may suggestthemselves from the description to follow, a better understanding of the in- .vention may be had by reference to the accompanying drawing, in which Fig. 1 is a fragmental cross section of the novel clutch pulley in the normal or idle position, and Fig. 2 is asimilar view of the pulley in the engaged or driving position.

While various clutch pulleys are found in the prior art, few appear to be designed on a basis of eiiiciency. In some a multiplicity of parts exists, others are bulky or extensive, and still others are doubtful of operative efficiency. I have found that a pulley of this kind to be acceptable in a. modern'lsense must avoid the deficiencies just mentioned ,andprove practical from every point of view. The clutch pulley I have devised isof value forlight machinery, such as for small drill presses, power sewing machines and light-tools in which a clutch is desirable, and

for these purposes the novel clutch pulley accomplishes the objects outlined above.

In accordance with the foregoing,- specic reference to the drawing indicates the shaft of the machine or unit operated by the pulley at I0. This shaft has a bearing, preferably of the roller type indicated at I I, for the mounting of the driving or loose pulley member I2, which is in the f form of a. heavy circular disc. The driven' member I3 of the pulley is alsoa disc formed with -a hub Isa which is sndamy keyed at I4 to me shaft. so as to be movable to'ward and from' the member I2. A fork shifter I5 is shown for this operation, but any other suitable means may be employed which will advance the driving member to 5 engaging position and maintain it there. The driving member I2 is formed with a peripheral ared groove I2a suitable to receive a V-belt I6. While the outer` wall of the groove is entire, the inner one is cut away to about half 10 the depth of the groove, appearing as aange I2b.

I The member I3 is extended with a short flange I3b in the direction of the belt I6, the flangeV occurring slightly beyond the flange I2b in a radial direction and having its inner face beveled 15 in parallelism to the contiguous face of the belt. With the parts shown as 4in Fig. 1, theclutch member I2 may be considered as receiving continuous motion from a motor, line sha'ft or other power source, by way of the belt I6. The mem- 20 y A ber I2 thus runs as a. loose pulley, and has no effect on the shaft I0. However, when the? driven memberJI-I is urged in the direction of the mem-J ber I2, the beveled face of the flange I3b comes 'into contact with the belt I6 with some pressure, 25

.A the belt causes the same to closeabout the pulley and sink more/deeply in its groove until the load is fully assumed, as is indicated by .dotted lines in Fig. 2. This travel of the belt causes it to wedge more tightly between the beveled forma- 35 tions ofthe co-acting members, resulting in a driving member I3, but occurred from the pull on 40 the belt by the power source, around the member I2, in assuming the load referred to. It is thereyfore seen that only a light initial pressure is necessary to actuate the clutch, the power drive fol-` lowing With a far stronger eiort to .firmly engage 45 the clutch members.

It is further evident that a high leverage fo the clutching action is secured by having the same in a zone farthest from the center of the pulley. Also, the flange I2b serves as a retainer 50l for the belt without the necessity of aspcial pulley or support for the inner side of the same. Further, the -groove is of sufcient depth to permit the advance of the belt in c it suffers wear, so as to prevent slippage, the take-up being both lg55 automatic and efcient owing to the wedge shape and ample cross-sectional size of the belt.

It will also be appreciated that the present clutch has no facings to replace, the belt and clutch members suillcing to take up wear as pre viously mentioned. Also, owing to the very slight' longitudinal travel necessary for .the driving member I3, the entire pulley can be built very-` short and therefore takes up a minimum of space. Finally, it'will be apparent that'the simplicity and ruggednessl of the present clutch pulley will enable it .to be manufactured at low cost Aand to serve indefinitely without appreciable attention or repair.

1. A clutch comprising a driving pulley, a shaft freely mounting said pulley, a driven member laterally spaced from said pulley and slidably'keyed' to said shaft for movement towards. and away from said'pulley, a peripheral groove having diverging walls formed on said pulley, one wall of said groove being lower than the other wall, a belt carried in said groove by said walls thereof, and

"said driven means being formed to provide means for engaging said belt above the top of said lower wall to frictionally connect said driving and driven members when the latter is slid along said shaft into engagement with said driving member.

2. 'I'he structure of claim 1, said .belt normally being supported by said walls of said groove above the floor thereof but being adapted to be wedged further into said groove upon the increase of the load thereon induced 'by the engagement of thev belt-with said means on said driven member. j 3. 'I'he structure of claim 1, said beltbeing of substantially V-shape in cross-section to conform to the divergence of said walls. A

4. I'he structure of claim 1, said belt being of substantially. v-shape in cross-section to conform to the divergence of said walls. said means on said driven member comprising a circularflange extending laterally therefrom and havingy its belt engaging face beveled to conformto the angle of divergence of said lower wall.

5. The structure of claim 1, said belt being of substantially V-shape in cross-section to conform to the divergence of said walls, said means' on' ROBERT nBRowNLEE. 4 

